Systems with persistent disturbances: predictive control with restricted constraints

This paper addresses predictive state regulation of linear discrete-time sy stems subject to persistent bounded disturbances and to state and/or contro l constraints. It is well known that the joint presence of constraints and disturbances can drive a predictive controller to infeasibility and instabi lity. Here it is shown how robustness against persistent bounded disturbanc es can be enforced by inserting in the predictive controller suitable const raint restrictions. The robust predictive controller obtained in this way g uarantees, for all admissible disturbances, constraint fulfillment and asym ptotic state regulation, i.e. convergence of the state to a minimal robust invariant set, provided that the initial state is feasible. Simulation resu lts demonstrate the effectiveness of the proposed approach. (C) 2001 Elsevi er Science Ltd. All rights reserved.